Welsh actor Matthew Rhys has landed the leading role in an upcoming HBO drama.

Rhys, fresh off his Critics’ Choice Awards win for his part in The Americans, will play the title role in Perry Mason as a defence lawyer representing the wrongly accused.

76th Annual Golden Globe Awards – Fox Afterparty
Matthew Rhys, pictured with partner Keri Russell, has landed the lead role in a HBO series (Chris Pizzello/Invision/AP)

The original series first aired in the US in the 1950s and the Rhys version is reportedly an origins story set in Los Angeles in 1932.

Iron Man star Robert Downey Jr is the executive producer and revealed Rhys’s involvement on Twitter.

Alongside a picture of front page of the script, Downey wrote: “Now it seems to me the place to start is at the beginning.

“And it seems to me the beginning of any great project is casting my new best friend Matthew Rhys.”

Cardiff-born Rhys, 44, has won an Emmy Award for his portrayal of Philip Jennings in FX’s spy thriller series The Americans.

He won best Actor in a drama series at the Critics’ Choice Awards on Sunday.